1. Field of the Invention
The present invention relates to a cell-phone terminal, a program management method and a computer program thereof for controlling a plurality of programs.
The present application claims priority to Japanese Patent Applications No. 2004-100267 filed Mar. 30, 2004, No. 2004-100268 filed Mar. 30, 2004, and No. 2004-100269 filed Mar. 30, 2004, the contents of which are incorporated herein by reference.
2. Description of Related Art
According to a conventional technique, thread histories about processing application programs are stored on a memory of OS (Operating System) in order to have a multitask-like operation performed on a single-tasking operating system. The operating system monitors whether or not there is the application program requesting an operation next with a timer. In the case where there is an application program which is requesting the operation next, the operating system adds the application program to the thread history and after that, switches control to the application program.
In the case of switching to operate the application program originally used again, it is implemented in a form such as the accumulated thread history is read in order from the one accumulated earliest and the process is switched one by one (for example, patent document 1: Japanese Unexamined Patent Application, First Publication No. H06-44084).
A technique shown in patent document 1 is an example of control on a personal computer having more sufficient processing power and a lower occurrence rate of unexpected interrupt control such as an incoming call than a cell-phone.
According to the conventional technique for the cell-phone, even if an instruction to run a plurality of application programs is specified by use of the timer, it is not possible to start processing a next application program unless each of processes is completed. Furthermore, it is not possible to hold a plurality of previous statuses of the application programs, either. For that reason, in the case of the cell-phone terminal in patent document 2 (Japanese Unexamined Patent Application, First Publication No. 2003-319020) which is the conventional technique, the application programs are individually monitored and controlled according to a type or a status thereof on occurrence of an event such as the incoming call.
As described above, however, the technique in patent document 1 is that on the personal computer having the lower occurrence rate of unexpected interrupts than the cell-phone. It has a problem in that the technique can only read the accumulated thread history in order from the one accumulated earliest. The cell-phone terminal in patent document 2 has a problem in that the control has to be implemented for each individual application because the control is executed according to the type and status of each individual application.
Furthermore, the technique in patent document 1 also has a problem in that, on occurrence of the interrupt, it only switches to a process in a standby status and it does not apply the control in consideration of conflicts of conditions among a running program and a program to be run. The technique in patent document 2 has a problem in that, while it determines the process of an interrupt event based on the type and status of the application program, no consideration is given to a conflict determination process applicable for a plurality of application programs.
The technique in patent document 1 is one in which a personal computer has a lot of memory, where it is easy to add the memory even if application programs are added and the conflicting conditions increase. The cell-phone terminal has a problem in that its memory is limited and it is difficult to increase the memory easily. The technique in patent document 2 has a problem in that the process of the interrupt event is not considered of the amount of memory.